// -----------------------------------------------------------
// set up mouse monitoring

var circle_mouseX;
var circle_mouseY;

function recordmouse(e) {
  // check for IE
  if(document.all?true:false) {
    circle_mouseX = event.clientX + document.body.scrollLeft
    circle_mouseY = event.clientY + document.body.scrollTop
  // if not, assume "normal" mozilla mode
  } else {
    circle_mouseX = e.pageX;
    circle_mouseY = e.pageY;
  }
}

document.onmousemove = recordmouse;